1. Field of the Invention
The present invention relates to a sense amplifier circuit that amplifies a read signal for reading an EPROM (erasable programmable read-only memory) for use in a sensor circuit.
2. Description of the Related Art
A sensor circuit for adjusting the sensitivity and/or the output signal power of a sensor usually includes an EPROM and a sense amplifier circuit. Usually, one sense amplifier circuit is provided for a plurality of cells of the EPROM in order to reduce the cost and the size of the sensor circuit. In this sensor circuit, however, the amount of current flowing through the sense amplifier circuit changes whether the EPROM has been written (“1”) or not (“0”) when the EPROM is read.
If one sense amplifier circuit is provided for each one of a plurality of cells of the EPROM to eliminate the difference between the written states of the EPROM, the size of the sensor circuit becomes larger, especially in the case of the sensor circuit being formed in one chip.